The present invention relates to a high flow, low pressure oil-free blower of heavy gases, and in particular, to an internal blower used in photolytic atomic iodine lasers. Typical gas lasers such as CO.sub.2, CO, HF/DF and photolytic iodine lasers require a flow of the gas medium in order to remove gas heating or discharge/photolytic by-products. For open cycle lasers where the gas is not recirculated, there exists many types of blowers and pumps exhibiting good pumping capacity for pressures greater than a few tenths of torr as illustrated in FIG. 2. These blowers, FIGS. 2A and 2B, for example, are not suitable in closed cycle gas handling systems requiring minimal contamination because the rotating seals and bearings are oil lubricated. For high pressures (&gt;100 torr), closed cycle laser systems, a vane-axial fan blower using ferrofluidic seals have been used with some success. Unfortunately, at pressures below 100 torr, no blowers exist having any reasonable pumping capacity to produce high flow velocities without creating gas contamination. A CW or pulsed photolytic atomic iodine laser at 1.315 microns uses a very heavy molecule C.sub.3 F.sub.7 I as the starting gaseous species for promoting lasing. Previously, only passive C.sub.3 F.sub.7 I flow systems have been used providing flow velocities of only 1-2 m/sec. For higher power cw and higher repetition rate pulsed photolytic iodine lasers, much higher flow velocities are required along with small pressure variations. In addition, its employment with an evaporative/condensative system for providing clean C.sub.3 F.sub.7 I laser fuel creates another critical innovation. This is the resultant large gas compression ratio since the inlet gas pressure is low (fractions of a Torr to a few Torr) from the condensative/evaporative fuel system and the outlet gas pressure is much higher pressure, typically a factor of 10 to 20 and greater. To overcome these limitations, an internal blower capable of flow velocities greater than 10 m/s for the C.sub.3 F.sub.7 I while operating at relatively low pressures but still constant of 5 to 60 Torr is required. Significant complications arise, however, since the C.sub.3 F.sub.7 I is a very massive molecule of 293 amu (atomic mass units). Previous pumps operating at very fast rpms (.about.20,000) had rotors interleaved between stators which provided excellent pumping capacity for pressures of 10.sup.-9 to approximately 10.sup.-3 torr. FIG. 5 shows typical pumping curves for such turbo-molecular pumps. The loss of pumping capacity for pressures greater than a millitorr occurs because the torque power provided by the internal motor of conventional pumps is insufficient to pump the higher gas densities experienced as the pressure increases. Another deficiency of existing turbo-molecular pumps is the oil-lubricated bearings and elastomer or O-ring rotating seal. Many of these pumps overcome oil contamination problems by exhausting gas to the external environment through the rotating seal 84. Two conventional non-contaminating blowers being the piston drive and centrifugal could not simultaneously produce the flow velocity at low pressures (5 to 60 Torr) with small pressure fluctuations and negligible gas contamination from oil vapor in sustained operation with this heavy molecular gas. These problems prevented their use as an internal, closed cycle blower of gases at pressures in the 0.1 to 100 torr range while still providing contamination-free gas with high gas compression ratios.